Foam-inhibiting and foam-inhibited compositions



atent United States F we 2,702,793

mosilane to triphenylbromosilane, the fluoroanalogs rang- 2,702,793 ing from trietlllylifluorcisilane to tlr1ibenz%lfiuo1loslillalhe, a'nld 'dt'l hr'e,uc as'enzet r- FoAM-mHmITmo AND FOAM-INHIBITED ;,f,;,,, 2, an s S y yp COMPOSITIONS 5 The dialkyldihalosilanes as represented by dimethyland diphenyldibromosilane, the alkyltrihalosilanes as repre-v g gg ga ?.Z% N s fgg 2 sented by methyltrichlorosilane and the alkylalkoxysilanes Delaware compounds which is preferred include amyltriethoxysilane, No Drawing Application June 13, 1950 10 monomethyltriethoxysilane, diisopropyldiethoxysilane,.diserial No. 167 915 n-butyldiethoxysrlane, trramylethoxysllane, trr- 2-. ethylhexylethoxysilane and monolauryltriethoxysilane. 1 Claim. (Cl. 252-78) The organo-silicon oxide condensation products or condensation products of silanols or organo-silicols -referred This invention relates to improvements in foamto herein are intended to include both silicones'and inhibiting compositions and foam-inhibited compositions, silicates, preferably normally liquid, of the following particularly those compositions containing hydrocarbons. general compositions:

In certain liquid compositions such as hydrocarbon oils R R used forthe lubrication of engines, in automatic trans- A 1 missions for automotive vehicles, as hydraulic oils or for (Silicone) similar purposes, the problem of foam or froth has been n serious because of the loss of oil due to expansion and overflow, anl the starg ationl of friction surface? %s respects OR 0R lubrication ecause o the arge proportion o oam content of the oil. Foam or froth has also been a problem RO SP0 gPOR (511mm) in chemical and petroleum processing since large quanti- 0R 0R ties of foam reduce the quantities of material that may be handled in apparatus of predetermined capacity The wherein R represents, similar-or dlssrmrlar organic radicals various problems involved and some solutions therefore Such as alkyl, aryl alkaryl, aralkyl and heterocychc are fully discussed in Patents Nos. 2,416,503 and 2,416,504 groups; the tfirminal and Other M and Patented Feb. 23,, 1955,.

are also to be included. Examples of the latter'class of issued February 25, 1947, to C. E. Trautman et al., Patent may be substitutedby hydroxyl groups; and n is 2 375 007 issued May 1 1945 to Larsen et aL more. Such compounds and their methods of preparation: i. 2,406,671 issued August 27 1946, to to form compounds of di fierentviscoslties are well knownmond, and Patent Nos. 2,406,971 and 2,407,037 issued to the 1 Where R September 3, 19.46, to F SOWZL aromatic hydrocarbon grouping,- mtra-substrtuents such The above patents disclose the use of liquid organoasaflalogen zirtltrogeli'comammg mdlcal or silicon condensation products or polymers such as silicones a raqlcal Such as SO3H 9 or a phos' or silicates as foam-inhibiting agents in liquids having ,l radlcal such as phosphlte phosphate tendencies to foam, reference being made to the disclosures the denvauves may q of such patents for a description of the various composi- 40 Typlcaiyompounds Include. .hmethyl slhcone methyl tions used and their methods of preparation and use. R f slllcone ethyl l p q h cyclohexyl While the compounds disclosed in the foregoing patents slhcone dlcyclohieiyl slhcone dlphenyl iq hydroxy have proven generally satisfactory, it is an object of this Phenyl fli slhcone y propyl Simone .R invention to provide even more efficient foam-inhibiting lsopropyl Simone tolyl. .butyl slhcone tolyl amy1.s1hcne agents for-liquids having foaming tendencies. Phenyl hydroxy ethyl iand the corresgqndmg poly Another object of this invention is the provision of a mers of methyl orthosllicate and ethyl orthosihcate. Comrelativelycheap and eflicient anti-foaming agent capable Pounds containing Simple organic radicals such as methyl of inhibiting foaming of liquids used for special purposes ethyl and Short cham alkyl groups are Preferred Such such as inth'e hydrocarbon oils used in automatic transcompmlnds may have hydroxyl groups organic radicals missions for automotive vehicles. as termmals' f I Other objects and advantages of the invention will ap- Th compounds are Pre f z mcorpqrated the pear from the following description and the accompany- Posmon to be treated b mlxmg i Wlth a hlgh bolhng ing e1aims naphtha such as kerosmeand Il'llXlIlg the resultant com- In brief, the present invention resides in the discovery bmatlon Wlth the q i that an improved foam-inhibiting agent can be formed by A pyeferred organoslhcon p t 1s a hm-ethyl $111 the use of liquid organo-silicon condensation products or v P P t Wlth methyl H rpolymers in combination with a silane. It has been found i i bemg .mlxed with il finely dlvlded that by the addition of a small proportion of a silane t q mammal i finely dlvlqed q to the foam-inhibiting agents disclosed in the above patslon 15 formed Whlch relatweiy Inert. contaqt Wlth cuts, a more efiicient foam-inhibiting agent can be formed. known metals iq and 1s relatlvely fl e term as used herein is intended to cover mable. If desired, the siliceous materialjmay be omitted. organic derivatives of a hydride of silicon of the type above organo'slhcon compounds {nay i SinH21t+2. It is intended to include compounds having the Viscosity from 100 to ZSOzOOO the hlgher vlsCoslty following general formula: compounds above 900 cs. being usually preferred.

X so-called Carnegie Foam Test which has come to be generally recognized as one of the most drastic tests developed I thus far. In this test which has been developed primarily X for the testing of oils used in hydraulic transmission mechwherein X is R or OR and R represents imila di anisms and the like wherein the conditions are ideal for 65 The tests hereinafter described were conducted by the' similar organic radicals such as alkyl, aryl, alkaryl, aralkyl the production of foam, the oil being tested passes through and heterocyclic groups. Typical examples are coma pump having a submerged intake and an'air-open dispounds of the type SiR4 such as silicon tetramethyl, silicon charge ab ve the body of il- Simultaneously tWO P tetraethyl, silicon tetraphenyl, silicon tetrabenzyl, and silipellers are used to agitate the oil body. The oil is heated con tetrapropyl. Compounds containing mixed radicals, to a temp 0f ab011t200 F- i. e., different aliphatic and aromatic groups are exempli- After the oil is brought to temperature, the propeller fied by tripropylallylsilane. Another type of silane is the motor is turned on'and the pump discharge pressure set alkylsilane such as trimethylsilane, triphenylsilane, triat 40 lbs. per square inch. After one minute, the motor ethylsilane, tri-i-butylsilane and tri-i-amylsilane. Other 18 shut off and the height of foam, i. e., the distance from types ,of silanesare the alkylhalosilanes ranging from trithe top of the foam-to the oil-foaminterfaceis meas methylchlorosilane to trrbenzylchlorosilane, ,triethylbro ,ured. The :foam collapse time is .takenas-the time.-elap s ing between the stopping of the motor and the first appearances of the oil surface through the foam. The foam height is reported to /s" and the foam collapse time to one second. Approximatelysix quarts of oil is required for the test.

As already described. the present invention is concerned with a foam-inhibitor prepared by mixing a liquid organo-silicon condensation product or polymer with a silane. The results obtained in inhibiting foam bv the use of such a combination have proven to be much better than the'results obtained by using either tvpe of compound separately. As a matter of fact, silanes per se are of practically no value in inhibiting foam.

As an example of the hi h and entirely unexpected efficiency of the invention. a hydraulic transmission fluid was prepared with a mineral oil base. About 3.5 to 4.5% of an additive of the methacrvlate nolvmer type, about 2.5 to 3.5% of an additive of the sulfurized sperm oil t pe and about 0.8 to 1.0% of an additive of a barium thionhosphate-sodium sulfonate tyne in a light oil as a carrier. all by wei ht, were added to a base compound formed of a refined paraflin base oil having a viscosity S. S. U. at F. of about 100.

The methacrvlate polymer type additive contains approximately 40% of a polymerized ester of methacrylic acid having a molecular weight between 10,000 and 15,000 and of the following general formula:

wherein R is a mixture of cetvl, lauryl and octyl groups. The additive is formed by dissolving the polymer in a Mid-Continent solvent-refined 150 neutral oil. The result is a clear, li ht-amber colored viscous fluid having a Sp. Gr. 60/60 F. of 0.890.90, and flash point F., diluted to solids with a S. A. E. 20 oil, COC. of 405 min., a viscosity, Kinematic at 210 F., cs. of 600- 800 and a Neut. No. of 0.4 max. This additive has been found valuable as a viscosity index improver and a pour point depressant. I

The sulfurized sperm oil type additive can be described as having a sulfurized sperm oil and lanolin base, the principal constituent being a sulfurized derivative of cetyl oleate:

'IZC15H330GO CH2)7CH CH3(CH2)7CH It is probable that the sulfur enters the molecule at the double bond to form a ring structure somewhat as follows:

The additive has a gravity APT of 14.5-16.0; a viscosity S. U. S. at 210 F. of 190 to 230 seconds, and a saponification No. of 140-155. The sulfur content is about 9 to 11% by weight. In addition to functioning as an extreme pressure lubricant, the additive also functions as an oxidation inhibitor and as a mild detergent.

The barium thiophosphate-sodium sulfonate type additive is formed of approximately 12% sodium sulfonate, about 45.5% light lubricating oil as a carrier and about 42.5% of a barium compound of the following type:

. oil alone and no anti-foam agent, the foam was 1% The solution was mixed with the fluid in a proportion to provide a silicone content of 2.5 parts per million.

The fluid was then tested by the Carnegie Foam Test with the following results:

Foam, Time, Inches Seconds With another test with only 1.0 p. p. m. silicone, the foam was A and the time 33 seconds. With the basic and the time 35 seconds.

An anti-foam agent according to the teachings of this invention was prepared by adding suflicient kerosine to 10 grams of the same silicone and 20 grams amyltriethoxy-silane a proportion of 1 to 2 by weight to make a total volume of ml. the same fluid inamounts to make separate samples containing 1.0, 2.5 and 5 p. p. m. silicone (3, 7.5, and.

15 p. p. m. of silicone plus silane). These mixtures were testeld by the Carnegie Foam Test with the following resu ts.

From the above, it is evident that silicone without the silane even when used up to 2.5 p. p. m. was only partly efiective in inhibiting foam. On the other hand, with as little as 1.0 p. p. m. of the silicone in the siliconesilane combination, there was complete inhibition. On a comparative basis, the silicone-silane combination can be said to be 2.5 times as effective as the silicone alone.

The above-described fluid is a particularly good hydraulic transmission fluid in that it is capable of transmitting power efficiently through either the fluid coupling or torque converter, it is an eflicient lubricant for the complicated and precisely machined moving parts such as the various pump units involved, and is capable of satisfactorily lubricating and preventing wear on any gearing contained in the transmission unit. cosity and a pour point of at least 35 P. which satisfies the requirements of temperature extremes liable to be encountered. It is stable in service, resistant to oxidation and deposit formation, and resistant to foam formation and gas entrainment which could interfere with the efficiency of the power transmission.

Application of the invention to other special-purpose oils as well as the usual lubricating oils is also contemplated. One such special-purpose oil is a lubricating oil prepared for use in diesel engines by combining a base oil (having a gravity, API of 22.5-28.5, flash, C. O. C. min. 420 F., fire, C. O. C., min. 470 F., viscosity, S. S. U. at 100 F. of 540-630, viscosity index 76 min., pour point 5 F. max.) with about 16.5% by volume of an additive classified as a basic barium sulfonate, barium dithiophosphate, sulfurized terpene product, the latter being particularly valuable in counteracting the corrosive effects of high sulphur fuels.

Other special-purpose oils include industrial gear lubricants, refrigerator oils and rock-drill lubricants.

It should be noted that the present invention is concerned with the inhibition of gas or air entrainment as well as the inhibition of foam. Foam is the frothy liquid and gas mixture formed on the surface of the liquid. It is readily distinguishable from the liquid proper, the separation taking place at a liquid-foam interface. Air or gas entrainment is not readily determinable and involves an actualincrease in the volume of the liquid because of the air or other gas entrained therein. Tests have proven that there may be gas entrainment in the absence of foam.

Use of the foam inhibitor of the present invention is also contemplated in anti-freeze liquids of the type to pared from the various types of water-miscible polyhydric alcohols including ethylene and other glycols, poly- This mixture was added to- It has the correct vis-' glycols and glyeerine. In some instances, the resultant mixtures in the engines have been found to foam to an extent such that the mixture escapes from the cooling system to a degree sufficient to seriously affect the operation of the engine. Consequently, the inhibition of foaming of such mixtures is desirable.

In incorporating such a foam inhibitor in an anti-freeze mixture, such as one of the ethylene glycol type, reference being made to the co-pending applications of T. C. Heisig, Serial No. 84,259, filed March 29, 1949, now abandoned, and Serial No. 138,513, filed January 13, 1950, for a more complete description thereof, the glycol if such used, is usually mixed first with any desired corrosion inhibitors in water solution to provide a mixture containing about 92 to 97% glycol. The organic-silicon compound and the silane may then be blended with a suitable hydrocarbon to obtain the final specific gravity desired, and the resultant anti-foam mix added to the glycol and water mixture in an amount between 0.90 and 1.25%, preferably about 1.05% by volume. The resultant anti-freeze is subsequently mixed with from 1 and /2 to 4 times its volume of water to provide the final coolant dependent upon the desired depressing of the freezing point of the coolant.

In addition to the above, the anti-foam agents herein described may be used in other types of hydrocarbon compositions including special solvents, gasoline, kerosine, cleaning fluids and turbine oils. Their use is also contemplated in such substances as latex, resins, paints, perfumes, synthetic and natural oils, vegetable oils and fats, animal oils and fats and cutting oils such as those of the soluble type which contain emulsifying agents and are diluted with water.

Their use is also contemplated in connection with foaming as found in oil and the water emulsions, in connection with the various processing steps of various substances such as distillation, fraction, concentration, filtration, solvent extraction, emulsion breaking, evaporation and condensation.

In summarizing, it is believed evident from the above that applicant has provided a new and exceedingly efiicient foam inhibitor. In addition it should be noted that the silane in the inhibitor is a much cheaper ingredient than the organo-silicon compounds, this making the final composition cheaper than those used heretofore.

The reasons for the high and unexpected efliciency of the combinations of the invention are not understood. It may be that there is some chemical reaction between the silane and the organo-silicon compound productive of an entirely new compound. Therefore the terms mixture, composition or combination as used herein and in the claim is intended to cover both physical and chemical combinations of the various compounds used.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof and, therefore, only such limitations should be imposed as are indicated in the appended claim.

I claim:

A composition of matter of reduced foaming and gas entraining properties consisting essentially of a mineral oil characterized by a tendency to foam and entrain gas when agitated, and 3 to 15 p. p. m. of a foam and gas entraining inhibitor consisting essentially of both 100,000 cs. dirnethyl silicone and amyl triethoxysilane, said silicone and said silane being present in a proportion of 1:2 by weight.

References Cited in the file of this patent UNITED STATES PATENTS 2,129,281 Lincoln et a1 Sept. 6, 1938 2,375,007 Larsen et al May 1, 1945 2,406,671 Diamond Aug. 27, 1946 2,416,503 Trautman et al Feb. 25, 1947 2,416,504 Trautman et a1 Feb. 25, 1947 2,435,124 Bollinger Jan. 27, 1948 2,462,999 Scott Mar. 1, 1949 2,468,869 Daudt May 3, 1949 2,490,068 Lincoln et al Dec. 9, 1949 2,491,833 Sauer Dec. 20, 1949 2,561,178 Burkhard July 17, 1951 

